Hurricane Irma has devastated islands in the Caribbean, destroying homes and leaving several people dead. The prime minister of Antigua and Barbuda says that nearly all of Barbuda's structures have been damaged. Now the storm is headed to the U.S. mainland. A mandatory evacuation for the southern part of the state has been ordered and residents are packing up and heading north.

BRIT MOSES: All you see is people putting sandbags in front of businesses, boards in front of windows, hurricane shutters.

MARTIN: Brit Moses (ph) hit bumper-to-bumper traffic on her way out. She says cars trying to get gas were lined up all the way onto the highway.

MOSES: And now the gas has completely ran out.

MARTIN: It took Doug Finger (ph) 45 minutes to fill up his tank before he left with his wife and 4-year-old son. He's a Florida native, and he remembers living through Hurricane Andrew.

DOUG FINGER: When the governor said this is bigger, meaner, faster than Andrew, that kind of hit me. This is scary.

MARTIN: What worries him the most? He still has family in the Keys who are determined to ride out this storm.

FINGER: I'm struggling really hard to figure out why people would want to do that, especially my family.

MARTIN: Joining us now from Miami is NPR's Greg Allen. Greg, so you're there in Miami. Are you in a place that you expect to be evacuated at some point?

GREG ALLEN, BYLINE: I don't think we will be, but it's still possible. Last night the county mayor here in Miami-Dade County, Carlos Gimenez, issued a mandatory evacuation order for about 150,000 people who live right near the coast. And I'm a little bit inland from there. It also includes barrier islands like Miami Beach. That's 150,000 people out of 2.7 million people who live in the county. So it's still a, you know, fairly small group of people, small percentage, but a lot of people to put on the road. And the fear is flooding from storm surge, you know, which could overwhelm these communities. During Andrew, 25 years ago, we saw a 17-foot storm surge so you can see what we're thinking about.

MARTIN: So a mandatory evacuation has been ordered for some people. For others, the governor is just saying it's to your benefit to just get out. But are people leaving? I mean, are people heeding the evacuation orders?

ALLEN: I - well, you know that some people will not, of course. Some people are going to stay. But I've been surprised by the number of people earlier in the week who were saying, I'm getting out. Because I think the spectacle of what happened to Houston after Harvey, and the memories of Wilma in 2005 and Andrew 25 years ago, in 1992, are really on everyone's minds. I've heard many people talk about Andrew when I've talked to - been out talking to people.

So they're taking it very seriously. Preparations began real early. There are gas lines throughout the week. You can't find water and batteries in the store. So it's one of these things that's got people moving. The one thing in Miami city officials are concerned about, I'll mention, are construction cranes. There are more than 20 of them downtown, you know, building - at high-rise construction building sites. And they're designed just to withstand winds up to 145 miles per hour. But right now, as you know, Irma's winds are far higher. It's a Category 5 storm. So a city official warned residents who live nearby those cranes to maybe think about leaving their buildings.

MARTIN: I imagine a lot of people are focusing-in on the actual path of the hurricane because clearly that will determine how much damage happens.

ALLEN: Exactly right. I mean, yeah, right now it's on this westward path. And at some point, probably on Saturday or so, it's going to take a turn to the north. And when it turns, you know, when it turns is the important question. If it's a little bit - right now it could come right up the center of the peninsula and do damage to the entire state. It could go a little bit more east, a little bit more west, and that has implications for people wherever you live. So we're just all watching to see what's going to happen to this storm and what path it's going to make.